Program to check if N is a Enneadecagonal Number | C # program for the above approach ; Function to check if number N is a enneadecagonal number ; Condition to check if N is a enneadecagonal number ; Driver Code ; Given number ; Function call
using System ; class GFG { static bool isenneadecagonal ( int N ) { float n = ( float ) ( 15 + Math . Sqrt ( 136 * N + 225 ) ) / 34 ; return ( n - ( int ) n ) == 0 ; } static public void Main ( ) { int N = 19 ; if ( isenneadecagonal ( N ) ) { Console . Write ( " Yes " ) ; } else { Console . Write ( " No " ) ; } } }